Check the everymac.com web site for your model specifications. Things you say such as a Macbook Pro from 2004 are not consistent with model releases by Apple and what you can do strongly depends upon your model specifications.
Mac OS X: System requirements for the current version - http://www.apple.com/macosx/specs.html
Leopard 10.5 Technical Requirements - http://support.apple.com/kb/HT3759
Snow Leopard 10.6 Technical Requirements - http://support.apple.com/kb/SP575 - note by K Shaffer - http://discussions.apple.com/message/12921514 : "Some early Intel-based Macs can't use Snow Leopard 10.6 installers; of those, the Core Duo (not 2 duo) were suspect and had issues." - and a qualifier by "a brody" http://discussions.apple.com/message/13028822 : "I think that refers to the ones without at least 1 GB of RAM."
I made a mistake, you,re right. The 12" is a powerbook (titanium).
so looking at the link you send me (thank you for that), I am not sure I understand.
I have now 10.5 installed.
if I look t this link: http://www.everymac.com/systems/by_capability/maximum-macos-supported.html
It seems to be the maximum version for this one.
BUT for the other one: it is a
MacBook Pro 15" (not 17" sorry this is the third one!)
Model Identifier: MacBookPro1,1
Processor Name: Intel Core Duo
Processor Speed: 2 GHz
So there is a LONGGGGG list but I am not sure what to look for exactly!
thanks in advance.
Any PPC Mac such as your 12" can only go to 10.5 maximum.
Get more information about your computer, go to the Apple in the upper left corner of any window, then "About This Mac", then "More Info..." Copy and paste the information here, but omit the serial number and Hardware UUID (if present). Also compare the information you get this way with the requirements for each system version I posted earlier.
If the MacBook Pro you have truly is only a CoreDuo then it can go to 10.6 but not higher.